1. Field of the Invention
The present invention relates to a chip collecting apparatus for a tip dresser for collecting chips generated when dressing electrode tips.
2. Description of the Related Art
Conventionally, electrode tips used for spot welding or the like are worn out (or deformed) when welding work is repeated. When welding work is performed with a worn-out electrode tip, welding of desired quality cannot be obtained; accordingly, electrode tips are periodically dressed to maintain welding quality.
For example, Japanese Unexamined Patent Application Publication No. 6-122082 discloses a tip dresser for dressing electrode tips in which after the upper and lower surfaces of a dressing body have been tightly pressed by a pair of electrode tips provided at opposed ends of a welding gun, and the welding gun is swung around the central axis of each electrode tip for grinding, thereby dressing the electrode tips.
Recently, the recycle of chips is contemplated in view of cost reduction and environmental issues. Accordingly, a collection vessel is disposed under the dressing body to recycle the collected chips.
However, there is a problem in that the chips tend to be released by the relative swing or rotation of the dressing body and the electrode tips during grinding work, and all the chips cannot be collected into the collection vessel, resulting in a low collection rate.
Furthermore, when air is blown to the dressing body to prevent clogging of the dressing body, the chips are released by the blown air, so that the collection rate of the chips is further decreased.
Generally, copper is often used as an electrode tip for spot welding and the like. In order to maintain a proper welding quality, the frequency of grinding is increased to increase the amount of ground chips of the electrode tip, so that, in order to reduce material cost, it is necessary to increase the collection rate of the chips and effectively recycle them.
For this purpose, various techniques are proposed in which a chip collecting apparatus is mounted on the dresser main body having a dressing body for collecting chips generated during dressing the electrode tips.
For example, Japanese Examined Utility Model Publication No. 3-18067 discloses a technique of collecting chips generated during polishing or grinding electrode tips in such a way that a cover main body is mounted on a dresser main body, and an air inlet and an air outlet are formed between the upper and lower surfaces of the cover main body and the dresser main body. Compressed air after driving a dressing body held by a holder is guided through the air inlet to the holder, and then the compressed air is guided through the air outlet to a chip collection vessel connected to the end of the cover main body.
In general, the operation of moving the welding gun provided at the end of the welding robot toward the chip dresser is often memorized by teaching in advance.
However, when the cover main body for collecting the chips generated during dressing operation is mounted on the dresser main body, as in the above prior art, it becomes difficult to visually recognize the positional relationship between the electrode tips and the dressing body; therefore, it is necessary to temporarily remove the cover main body from the dresser main body and to perform teaching, posing a problem in increasing the number of processing steps required for teaching.
Furthermore, since the dresser main body is covered by the cover main body, the dressed state of the electrode tips cannot be checked from the exterior, causing inconvenience of being unable to check faulty dressing such as insufficient dressing and excessive dressing.